def fileTree = new DirectoryFileTree(root, patterns, TestFiles.fileSystem(), false)

        when:
        fileTree.visitStructure(visitor, owner)

        then:
        1 * visitor.visitFileTree(root, patterns, owner)
        0 * visitor._
    }

    def "root directory is empty - isReproducible: #visitor.isReproducibleFileOrder"() {
        given:
        def root = temporaryFolder.createDir("root")

            }

            @Override
            public void visitCollection(Source source, Iterable<File> contents) {
            }

            @Override
            public void visitFileTree(File root, PatternSet patterns, FileTreeInternal fileTree) {
            }

            @Override

        when:
        fileTree.visitStructure(visitor)

        then:
        1 * visitor.startVisit(_, fileTree) >> true
        1 * visitor.startVisit(_, { it instanceof FileTreeAdapter }) >> true
        1 * visitor.visitFileTree(testDir, _, _)
        0 * _
    }

    def testResolveAddsBuildDependenciesIfNotEmpty() {
        def resolveContext = Mock(TaskDependencyResolveContext)
        fileTree.builtBy("classes")

        when:

            void visitCollection(FileCollectionInternal.Source source, Iterable<File> contents) {
                throw new IllegalArgumentException()
            }


            @Override
            void visitFileTree(File root, PatternSet patterns, FileTreeInternal fileTree) {
                assert root == classesDir
                assert patterns.getIncludes() == includes
                assert patterns.getExcludes() == excludes

        fileTree = new SingleIncludePatternFileTree(tempDir.testDirectory, "pattern", spec)

        when:
        fileTree.visitStructure(visitor, owner)

        then:
        1 * visitor.visitFileTree(tempDir.testDirectory, _, owner) >> { dir, patterns, fileTree ->
            assert patterns.includes == ["pattern"] as Set
            assert patterns.excludes.isEmpty()
            assert patterns.includeSpecs.isEmpty()

        }

        @Override
        void visitCollection(FileCollectionInternal.Source source, Iterable<File> contents) {
            Assert.fail()
        }


        @Override
        void visitFileTree(File root, PatternSet patterns, FileTreeInternal fileTree) {
            Assert.fail()
        }

        @Override

        override fun visitCollection(source: FileCollectionInternal.Source, contents: Iterable<File>) {
            elements.addAll(contents)
        }

        override fun visitFileTree(root: File, patterns: PatternSet, fileTree: FileTreeInternal) {
            elements.add(directoryFileTreeFactory.create(root, patterns))
        }